Let L-13 accident near Adelanto, California, September 29, 1991
On September 29, 1991 at about 8:40 pm local time, a Let L-13 (glider), registered N86661, was substantially damaged in an accident near Adelanto, California. It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
IMPROPER PLANNING/DECISION BY THE PILOT. LOSS OF THERMAL LIFT WAS A RELATED FACTOR.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 29, 1991 · about 8:40 pm local time
- Place
- Adelanto, California · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Let L-13 · all L-13s on the register
- Registration
- N86661 · no longer on the register · serial 25423
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE CERTIFICATED PRIVATE PILOT AND A PASSENGER WERE ON A LOCAL AREA GLIDER FLIGHT AFTER BEING LAUNCHED BY AERIAL TOW AIRPLANE. WHILE RETURNING TO THE PRIVATE AIRSTRIP, THE PILOT WAS UNABLE TO MAINTAIN THERMAL LIFT AND DECIDED TO MAKE A LANDING ON A DIRT ROAD. DURING THE LANDING ROLL, THE RIGHT WINGSTRIP STRUCK HIGH VEGETATION, CAUSING THE GLIDER TO PIVOT TO THE RIGHT INTO UNEVEN TERRAIN. THE RIGHT WING AND EMPENNAGE WERE DAMAGED.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane; rotorcraft: glider
- Flight time: 2,268 hours in all; 90 in this make and model; 24 in the last 90 days; 7 in the last 30 days; 2,065 as pilot in command
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: rear
The aircraft
- Airframe total time: 1,230 hours
- Last inspection: annual inspection, May 18, 1991; 57 hours since
- Maximum gross weight: 1,100 lb
- Seats: 2
- Landing gear: retractable
- Engine: (type not recorded); 0 hours total
- Operator: Big Wing Flyers INC.
The flight
- Departed from: NONE Adelanto CA at 8:40 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 090° at 7 knots
- Visibility: 50 statute miles
- Sky: scat at 7,000 ft
- Temperature: 90°F (32°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.